The present invention is directed to an improved weft yarn fork particularly adapted for application to a warp knitting machine which makes it possible to stop the machine whenever a yarn breaks or is subjected to excessive tension. In either case, the machine will stop automatically so that a single operator can control several machines.
The improved weft yarn offers countless advantages over those of the conventional type allowing one employee to control several machines in that the constant monitoring of every yarn is unnecessary since the stoppage of the machine will be automatic thereby allowing the fault to be corrected before a defect of substantial proportions results.
The problem with weft yarn forks of the conventional type resides in the manner in which they are fitted which consists of putting them astride each yarn. This makes it necessary to introduce the yarns into the weft yarn forks one by one, a slow manual operation which delays starting of the machine. In contrast, rapid threading is possible with the weft yarn fork according to the present invention, thereby providing an improvement in productivity.
The improved weft yarn fork according to the present invention makes it possible to stop the machine not only when a thread breaks, which is comparable to conventional weft yarn forks, but also when one of the threads is subjected to excessive tensile stress generally due to abnormal unwinding of the thread from its cone or spool. This excessive tension likewise tends to cause a defect in the fabric and this is prevented since the weft yarn fork detects it and immediately stops the machine.
The size of the blades of the weft yarn fork and their extreme thinness makes possible the production of fabrics having a high density of yarns per centimeter and the yarns can also be of very fine gauge. All of this is beyond the usual capability of convention weft yarn forks.